Numbers Questions

Product of digits of a 2-digit number is 18. If we add 63 to the number, the new number obtained is a number formed by interchange of the digits. Find the number.

Find the average of all prime numbers between 20 and 50.

What is the sum of the first 13 terms of an arithmetic progression if the first term is -10 and last term is 26?

The 3rd and 6th term of an arithmetic progression are 19 and 37 respectively. What is the 13th term?

The 7th and 12th term of an arithmetic progression are -15 and 5 respectively. What is the 16th term?

If the sum of a number and its reciprocal be 2, then the number is

The co-ordinates of the centroid of a triangle ABC are (-1,-2) what are the co-ordinates of vertex C, if co-ordinates of A and B are (6,-4) and (-2,2) respectively?

What is the sum of the first 12 terms of an arithmetic progression if the first term is -19 and last term is 36?